1. Field of the Invention
The present invention relates to a technology for reducing noise leaking from an image forming apparatus.
2. Description of the Related Art
Image forming apparatuses such as copiers, printers, and facsimile machines internally include various noise sources. Those noise sources include motors, moving parts, sliding parts, rotating rollers and the like. Image forming apparatuses are typically placed in offices and if the noise of an image forming apparatus leaks outside of the image forming apparatus main body, it causes a nuisance to people working around it.
Particularly in recent years, with an intention of downsizing offices or enhancing efficiency of a business, sometimes desktop image forming apparatuses are arranged on tables close to office employees. Due to this, measures need to be taken to reduce the noise leaking from the image forming apparatus main body.
Some image forming apparatuses include a plurality of sheet feeders right from the beginning. In these image forming apparatuses, various types of recording sheets can be stacked in the sheet feeders and selectively used. However, some users do not need a plurality of sheet feeders and for them the image forming apparatus with a plurality of sheet feeders is unnecessary costly.
Image forming apparatuses are available in which only one, or two, sheet feeders are provided right from the beginning; and one or more sheet feeders can be added at a later stage. A lower surface of such an image forming apparatus has an opening that leads to a sheet feeding path of the optional sheet feeder. However, noise produced in the image forming apparatus main body leaks to the outside from this opening and from a gap between the lower surface and the installation surface.
Related arts have been disclosed in Japanese Patent Application Laid-open No. 2001-356657, Japanese Patent Application Laid-open No. 2005-305653, Japanese utility model application Laid-open No. H3-093130, Japanese utility model application Laid-open No. H3-037449, and Japanese utility model application Laid-open No. H5-138987. In Japanese Patent Application Laid-open No. 2001-356657, a special member is used to seal the gap between the lower surface of the image forming apparatus and the installation surface. In Japanese Patent Application Laid-open No. 2005-305653, Japanese utility model application Laid-open No. H3-093130, Japanese utility model application Laid-open No. H3-037449, and Japanese utility model application Laid-open No. H5-138987, a special sound insulating member is arranged between the lower surface of the image forming apparatus and the installation surface. Thus, a special component is required for sound insulation in the technologies mentioned earlier. For reducing the work after arrangement, one approach could be to attach an elastic member to the lower surface of the image forming apparatus and in contact with the installation surface. In this approach the opening itself is not blocked. However, for this approach to be effective, the installation surface must be substantially flat. Noise insulation effects are not obtained if the installation surface is not flat. Moreover, because the elastic member is exposed outside the image forming apparatus, damage or deformation is likely to occur when manufacturing or packing the image forming apparatus and while handling the image forming apparatus after arrangement. Thus, constant sound insulation effects cannot be obtained.